The objective of this project (PJ1) is to propose resource management strategies that contribute to sustainability by analyzing various risk factors including environmental and social impacts of resource utilization engendered by Japan's economy through supply chains, and by formulating quantitative future scenarios based on those analyses.
Sustainable resource consumption and production calls for global management of resources and control of material cycles. Regarding metal resources, successful achievement of the United Nations' sustainable development goals (SDGs) and implementation of the Paris Agreement can be influenced by development of technologies for a low-carbon society, and these technologies require new infrastructure that consumes a mix of minerals that differ from the currently consumed ones. PJ1 analyzes the global resource networks from the past to the present, and even into the future, and identifies critical issues to consider, and make suggestions for the sustainable resource management (Fig.1).
Our research under the 4th NIES five-year plan has advanced the analyses of material flows and risks in global supply chain. Development of various analysis tools such as models and frameworks (Table 1) enables consideration of risk mitigation measures by identifying resource utilization and underlying risk factors related to the implementation of global warming countermeasures and other measures.
The following sections highlight PJ1's main achievements.
POINT: Global distribution amounts of used and unused mineral extraction generated by iron, copper, and nickel mining were estimated, and linkages between national economies and global impacts were demonstrated.
POINT: A panel data analysis demonstrated that an increase of base and scarce metal consumption has been associated with deterioration of some indicators measuring a progress of SDGs including social, economic and environmental targets.
POINT: The first systematic review was conducted on long-term dynamics of critical metals for 48 elements, and a comprehensive picture was obtained on the research progress in this field.
POINT: A total of 70 studies examining long-term outlooks for six major metals were reviewed, and a comprehensive picture was obtained on the research progress in this field.
POINT: Global targets for metal flows, stocks, and use intensity in the global economy to 2100 were developed. These targets are consistent with greenhouse gas emission pathways to achieve the 2℃ climate goal and cover six major metals (iron, aluminum, copper, zinc, lead, and nickel).
POINT: This research sets out to quantify the mortality and economic loss in individual Asian countries caused by the PM2.5 emissions induced by the consumption of the world's five highest-consuming countries (US, China, Japan, Germany, UK).
The objective of this project (PJ2) is to contribute to appropriate management of recyclable materials and accompanying substances that have hazard and resource potential as well as greenhouse effect (in the case of fluorocarbons) by understanding the actual emission and exposure in Japan and other Asian countries, especially with focus on waste electrical and electronic equipment (WEEE or e-waste).
The amount of recyclable resources increases along with the economic growth of Asia and the rest of the world, which necessitates efficient recovery of resources and prevention of environmental impact by means of appropriate recycling. In the cycles of recyclable waste materials, we should also pay attention to the management of their accompanying substances. In this project, we have focused on WEEE that has both hazard and resource potential as our main research subject because of the following reasons: the amount of WEEE has been increasing in the world; WEEE contains hazardous substances such as heavy metals and flame retardants; improper recycling of WEEE may produce dioxin-like compounds; and refrigerant fluorocarbons, a contributor to the global warming, are included in the accompanying substances of some WEEE such as air conditioners (Fig. 1).
The following sections present PJ2's three main achievements: (1) the development of future estimation model for WEEE, its application to air conditioners in Asia, and evaluation of the countermeasure scenarios for global warming mitigation; (2) the research results on direct and indirect exposure to chemical substances associated with WEEE dismantling and the results of risk assessment based on our field survey at informal recycling sites; and (3) our estimation result of WEEE plastic flows and behavior of contained flame retardants toward improving domestic recycling with consideration of China's waste import ban and its impact on Japan.
POINT: A model for estimating future WEEE generation was proposed based on the population balance model (PBM), and case studies were conducted to estimate future WEEE generation in Asian countries based on future scenarios of socio-economic indicators and product lifespan.
POINT: Chemical substances having higher priority in risk management of informal WEEE-dismantling and recycling were identified through their exposure and health risk assessment in Vietnam to mitigate negative environmental impact and improve safety of dismantling workers.
POINT: Flows of plastics originated from WEEE in their recycling process in Japan and the contained brominated flame retardants (BFR) were estimated for the fiscal year (FY) 2017. Although the mixed plastics export from Japan is considered to have decreased after China's waste plastic import ban, recycled pellets from WEEE plastics are still exported to China and other Asian countries. Nevertheless, a large proportion of BFRs were eliminated from the recycled plastics during the sorting processes.
The objective of this project (PJ3) was to develop a policy tool and propose further measures for establishing a circular society (or a Sound Material-Cycle Society) while adapting to various emerging social changes such as polulation decrease and aging. Our proposals were intended to retain proper waste treatment and advance circulation of materials and resources in the era of popuation onus.
Japan has implemented a circular society policy for three decades, especially since 2000, and successfully advanced its material circularity in terms of quantity. However, the progress is gradually saturating. Well-designed policy planning as well as improvement of resource circulation in terms of quality is needed. In addition, in such a situation, polulation decrease and aging are emerging in Japan, which causes various issues including inefficiency of waste management and recycling systems, financial difficulty, uninclusive garbage collection, etc.
PJ3 therefore covered three main research themes as a forerunner in the world: (1) population decrease and modelling of municipal waste management, (2) waste management in aging society, and (3) improvement of quality of resource circulation and efficient use of product stock.
To meet the above-mentioned objectives, we conducted case studies, developed material flow models, and analyzed current material use and waste treatment under diverse scenerios such as population decline, aging of society, changes occuring in local communities, and self-supply of energy.
The following sections highlight PJ3's main achievements.
POINT: A nation-wide municipal waste management model were developed for evidence-based policy making, especially for national target setting. The current recycling rate target of 28% in 2025 was proven to be unachivable. In the era of population decrease, policy mix of the promotion of recycling of food and plastic wastes and the reduction of incineration capacity is necessary, and ambitious policy implementation enables 23% of recycling rate in 2030.
POINT: Support needs for the elderly in waste disposal were clarified through field surveys, and a guidebook was published to support local governments and community-based organizations (CBOs) in designing and operating effective programs on this issue.
POINT: There were six patterns of quality improvement of resource circulation, and our attempt to quantify social values of a pattern confirmed its importance as well as methodological issues. Consumers' expected lifetime of electrical and electronic equipment was different from the actual lifetime by 50%, and effectiveness of the improvement of product durability was limited to 30-60% of cases examined.
The objective of this project (PJ4) is to develop and adapt technologies that suit Asia-specific situations and contribute to establishing a robust, sustainable, and integrated waste management system in Asia, including Japan.
In Japan and the rest of Asia, it is important to create a sustainable and resilient waste management system that is compatible with the region's specific environment, urban characteristics, economic conditions, and social acceptance. To achieve this, the region needs establishment of future waste treatment systems and methods for evaluating them that are in harmony with high-level urban planning. The region also requires development and upgrading of integrated technology systems for incineration, landfill, and other related technologies. This project (PJ4) develops and adapts technologies to suit Asia-specific situations for their wider application, and presents basic baseline models of waste treatment systems that can be customized to the Asian region.
During the 4th NIES five-year term, PJ4 developed and adapted several technologies for their wider application in Asia with the consideration of Asia-specific situations. The technologies include mechanical-biological treatment systems, constructed wetlands for landfill leachate, landfills with reduced long-term pollution flux, systems that save or generate energy by using decentralized wastewater treatment, and Johkasou (a household wastewater-treatment system) systems. PJ4 also developed and applied several tools for evaluating waste management in Asia.
The following sections highlight PJ4's main achievements.
POINT: Guidelines on composting and mechanical-biological treatment (MBT) were developed to assist decision-makers, policy-makers and other stakeholders in Asia in evaluating feasibility of these methods as strategic options for improving local waste management systems.
POINT: Energy-saving and decentralized waste and wastewater treatment technologies were developed and adapted for their wider application in Asian countries. Performance-testing, evaluation and certification systems for the treatment facilities were also proposed to specific countries in order to highlight technical and financial efficiencies of these technologies and promote their dissemination.
POINT: PJ4's study on the establishment and commercialization of a waste management system in harmony with urban planning proposed a business model for the phased introduction of resource recovery and sanitation facilities during the development of luxury residential districts or large commercial facilities in emerging Asian countries.
POINT: Development and adaptation of various MSW management and treatment technologies were examined, and the ones that suit Asia-specific situations (including Japan) and contribute to establishing a robust, sustainable and integrated waste management system in the region were identified.
POINT: Long-term environmental safety of the waste containing hazardous materials was investigated by evaluating effectiveness of various disposal and shielding methods used in landfills. Based on our findings, structural and waste disposal requirements were presented for landfills to improve long-term environmental safety.
The objective of this project (PJ5) is to develop next-generation waste-to-energy and waste-to-material technologies that can contribute to "3R (Reduce, Reuse, Recycle)".
The recycling ratio of waste is still not high in Japan, but some of the waste have potential to be utilized or recycled. Food waste with fat, oil and grease owns a high energy content and a great potential of producing biogas. Recovery of useful and harmful metals from bottom ash discharged from municipal solid waste (MSW) incinerators enables recycling of the residues (ash without those metals) as a construction material. In this 4th NIES five-year term, our research focuses on producing biogas from food waste and trap grease (waste-to-engergy technology), and recovering metals from ash discharged from incineration of municipal solid waste (waste-to-material technology).
We have developed waste-to-energy (WtE) and waste-to-material technologies (WtM). The research outcomes allow reduction of final disposal volume to be transported to landfills and strengthening of sound material-cycle society. They can also contribute to the implementation of Japan's national plan that promotes material cycles.
The following sections highlight PJ5's main achievements.
POINT: We developed a small-scale biogas production system that can significantly improve energy recovery efficiency using anaerobic co-digestion of food waste with fat, oil and grease.
POINT: Elemental composition of various incineration residues was analyzed to clarify behavior of useful and harmful metals during incineration of MSW and woody biomass. A method combining air-table sorting with particle size and density separations was found to be effective for recovering precious metals from bottom ash.